Circuit/System Description

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

The navigation radio communicates with the Color Display Module over the CAN Graphical Interface (CGI) serial data circuit. The CGI circuit is a UART - based serial data interface used to transfer messages and high rate display graphics.

When the Color Display Module is in the active state, the radio needs to determine if the module is communicating properly. The radio initiates the Display Status Message to the module and waits for a proper status response message back from the module. If after 30 communication attempts without a proper response, the radio holds down the reset circuit in order to reset the module.

This DTC indicates an internal ECU fault of the Color Display Module located on the Display Module Actuator. No external circuits are involved.